S,S-Dialkyl-O-alkylthioalkyl phosphites and phosphates

ABSTRACT

Phosphoric acid esters of the formula   wherein X denotes oxygen or sulphur, the integer n is the number 0 or 1, R&#39;&#39; and R&#39;&#39;&#39;&#39; independently of each other represent an alkyl radical with 3 to 5 carbon atoms and wherein A. IF X is oxygen, R represents an alkoxyalkylene, alkylmercaptoalkylene or alkenyloxyalkylene radical with at most 7 carbon atoms, and alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is substituted by halogen, methyl and/or methoxy, or wherein B. IF X is sulphur, R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group substituted by halogen, methyl and/or methoxy; these compounds are useful for defoliating and promoting the ripening of crop plants especially cotton.

United States Patent Beriger et al.

FOREIGN PATENTS OR APPLICATIONS S,S-DIALKYL-O-ALKYLTHIOALKYL PHOSPHITES AND PHOSPHATES Related U.S. Application Data Division of Ser. No. 105,125, Jan. 8, 1971, Pat. No. 3,760,042.

Foreign Application Priority Data Jan. 16, 1970 Switzerland 595/70 U.S. Cl.. 260/948; 71/71; 7l/87; 260/950; 260/951; 260/956; 260/963; 260/967 Int. Cl. C07f 9/16; AOIn 9/36 Field of Search 260/948 References Cited UNITED STATES PATENTS 2/1963 Schrader 260/948 X 2/1964 United Kingdom 260/948 969029 9/1964 United Kingdom 260/948 July 29, 1975 Primary Examiner-Anton H. Sutto Attorney, Agent, or Firm-Frederick H. Rabin [57] ABSTRACT Phosphoric acid esters of the formula n ll s R-X- l wherein X denotes oxygen or sulphur, the integer n is the number 0 or 1, R and R" independently of each other represent an alkyl radical with 3 to 5 carbon atoms and wherein a. if X is oxygen, R represents an alkoxyalkylene, alkylmercaptoalkylene or alkenyloxyalkylene radical with at most 7 carbon atoms, and alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is substituted by halogen, methyl and/or methoxy, or wherein b. if X is sulphur, R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group substituted by halogen, methyl and/or methoxy; these compounds are useful for defoliating and promoting the ripening of crop plants especially cotton.

5 Claims, No Drawings 1 S,S-DlALKYL-O-ALKYLTHIOALKYL PHOSPHITES AND PHOSPHATES This is a division of application Ser. No. 105,125, filed on Jan. 8, 1971, now U.S. Pat. No. 3,760,042.

The present invention relates to a special group of phosphites and phosphates that possess an activity for influencing the growth of plants, preferably a defoliating influence.

The invention further relates to the manufacture of these compounds and their use, as also to compositions that contain these compounds as active substances.

The new compounds correspond to the formula wherein X denotes oxygen or sulphur, the integer n is the number or 1, R and R" independently of each other represent an alkyl radical with 3 to carbon atoms, and wherein a. if X is oxygen,

R represents a branched or unbranched alkoxyalklene, alkylmercaptoalkylene or alkenyloxyalkylene radical with at most 7 carbon atoms, an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is optionally substituted by halogen, methyl and/or methoxy, or wherein b. if X is sulphur,

R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is optionally substituted by halogen, methyl or methoxy.

Among the phosphites and phosphates of formula I are certain groups possessing a particularly lasting biological activity, for example the compounds of the formula wherein R, represents an alkyl group with l to 3 carbon atoms, an alkenyl group with 3 to 6 carbon atoms, R represents an alkylene group with 2 to 4 carbon atoms, R, and R independently of each other represent an alkyl radical with 3 to 5 carbon atoms and the integer n is the number 0 or 1; furthermore, the compounds of the formula (ill) wherein R represents an alkenyl radical with 3 to 6 carbon atoms or an unsubstituted benzyl group or a benzyl group which is optionally substituted by halogen methyl or methoxy and R and R independently of each other represent an alkyl group with 3 to 5 carbon atoms, and X denotes oxygen or sulphur; also, the compounds of the formula wherein R represents an alkyl group with l to 3 carbon atoms, R represents an alkylene group with 2 to 4 carbon atoms, R; and R independently of each other represent an alkyl radical with 3 to 5 carbon atoms and the integer n is the number 0 or 1; in addition, the compounds of the formula s R, R, X P\S R4 (V) wherein X denotes oxygen or sulphur and R represents an unsubstituted benzyl group or a benzyl group which is optionally substituted by halogen methyl or methoxy or wherein X denotes oxygen, R,, is an alkenyl group with 3 to 6 carbon atoms, and R and R independently of each other represent an alkyl radical with 3 to 5 carbon atoms.

In the formulae I to V, the substituents R, R, R and R preferably denote the n-propyl or n-butyl radical.

In the formulae, I, III and V, the term halogen denotes chlorine, bromine and iodine.

ln U.S. Pat. No. 2,955,803, mono-, diand thrithiophosphites which are substituted by hydrogen, lower alkyl and/or aryl, have already been described as defoliants for crop plants. The commercially available tri- (n-butyl)-trithiophosphite iswe ll known, the activity of which is not satisfactory in practical application.

Furthermore, mono-, diand trithiophosphates, preferably those with lower alkyl radicals, are described in U.S. Pat. No. 2,965,467 as defoliants, of which tri-(nbutyl)-trithiophosphate has become known as a comproved by increased dosage.

Compared with these preparations, the group of compounds characterized by formula I exhibits considerable advantages, as the biological Examples detailed later on show.

In the case of plants that shed their leaves annually, abscission can be induced at any time desired by using compounds of formula l by themselves, or appropriately in the form of agents. lf plants, especially crop plants such as cotton, soybean, fruit-bearing trees, or ornamental plants are treated in this way, abscission occurs as a rule within 3 to 6 days. In general, ripening is thereby promoted simultaneously.

Favorable rates of application for active substances of formula I are in the order of 1 to 6 kg per hectare. It must, however, be taken into consideration here that degree of ripening, stage of development, climate, weather, nature of the soil and other influences, will suggest, if necessary, rather higher or lower rates of application.

The compositions according to the invention containing preferably 1-80 percent by weight of active substance can be applied in diverse ways, for example in the form of dusts, aqueous dispersions, aqueous emulsions, granules and so forth. They also contain as a rule one or more solid or liquid carriers or extenders. By extenders are to be understood solid or liquid diluents.

The compounds of formula I can be applied to the plants in inert media, for example as a dust, mixed'with a pulverulent, mineral carrier (for example mica, talc, pyrophyllite, clay) or they can be sprayed in aqueous form.

The agents are preferably also used mixed with small amounts of an anionic, cationic or non-ionic surfactant. Such an additive assists the dispersions of the compounds of formula I in water. The compounds can also be mixed with pulverulent carriers, such as mineral silicates, together with a small amount of a surface-active dispersing agent, in such a way that an easily wettable powder is obtained that can be applied directly to the plants or can be shaken with water in order to manufacture quickly a suspension of the chemical compound and of the pulverulent carrier in water.

The anionic surfaceactive substances which can be used with the present compounds or agents which influence plant growth correspond to the general formula RCOOM or RSO M. Herein M represents an alkali metal, an ammonium radical or a substituted ammonium or amine radical and R represents an organic radical which contains at least one group with more than 8 carbon atoms. Examples of such anionic, surfaceactive agents are:

l. Soaps, for example sodium laurate, ammonium stearate and diethanolamine oleate.

2. Alkaline sulphonates, for example sodium dodecylsulphonate and potassium cetylsulphonate.

3. Alkyl-sulphates, for example sodium docecylsulphate and sodium oleyl-sulphate.

4. Sulphonated ethers with long and short chains of aliphatic groups, for example C H O-C H SO -Na.

5. Sulphated ethers with long and short chains of aliphatic groups, for example C, H O-C H4O-SO3N3..

6. Sulphonated alkyl esters with long chains of fatty acids, for example 7. Sulphonated glycol-esters with long chains of fatty acids, for example 8. Sulphonated alkyl-substituted amides of fatty acids with a long chain 9. Alkylated arylsulphonates, for example sodium isopropylnaphthalenesulphonate and dodecylbenzenesulphonate.

10. Hydroaromatic sulphonates, for example sodium tetrahydronaphthalenesulphonate.

l l. Alkylsulphosuccinates, for example sodium dioctylsulphosuccinate.

l2. Arylsulphonate-formaldehyde condensation products, for example the condensation product of formaldehyde and sodium naphthalenesulphonate:

Non-ionic surface-active components which can be used for the present plant-influencing agents are, for example, the following:

1. Polyether-alcohols, such as for example the reaction products of ethylene oxide or polyethylene glycol with a fatty alcohol having a long chain, for example the reaction product of ethylene oxide and oleyl alcohol, C, H (OC H ),,OH, wherein n is 10 to 20.

2. Polyglycol-esters, for example the reaction products of ethylene oxide or polyethylene glycol with a fatty acid having a long chain, for example the reaction product of ethylene oxide or polyethylene glycol with oleic acid,

0 wherein n is 10 to 20.

3. Partial esters of polyhydric alcohols with fatty acids having a long chain, for example diethylene glycol monolaurate and sorbitane trioleate.

Cationic surface-active compounds which can be used for the plant-influencing active substances according to the invention are, for example, the followmg:

1. Quaternary ammonium salts, in which one of the groups bonded to the nitrogen is an aliphatic group with at least 8 carbon atoms, for example trimethylcetylammonium iodide, laurylpyridinium chloride, cetyldimethylbenzylammonium chloride and N- stearylbetaine.

2. Amines, amides, diamines and glyoxalidines which possess an aliphatic group which contains at least 8 carbon atoms, and their acid esters, for example stearylamine hydrochloride, oleyamide, diethylethyleneoleyldiamine and Q-heptadecyl-N-hydroxyethylglyoxalidine.

Furthermore, additional known defoliants, abscission accelerators or also growth regulators can be added to the active compounds of formula I in the practical application. Possible defoliants are, for example, tri-(nbutyl)-trithiophosphite (Folex), tri-(n-butyD-trithiophosphate (DEF), or Na-cis-3-chloroacrylate (PREP). Known growth promoting substances that can be added to the compounds according to the invention are: ALANAP, DURASET, PHOSPHON, VERNOLEPIN, o-furfurylaminopurine, naphthylacetic acid, B -indolybutyric acid, indolylacetic acid, fluorene-6- carboxylic acid andderivatives thereof, chlorocholine chloride, hydroxyethylhydrazine, cycloheximide, ascorbic acid, succinic acid-dimethylhydrazide, maleic acid hydrazide, 2,3,5-triiodobenzoic acid.

Together with the compounds of formula I, a satisfactory abscission accelerator is especially disodium-3,6- endoxohexahydropthalate, which has become known under the name Endothall.

The new phosphites and phosphates of formula (I) can be manufactured according to methods known per se by the stepwise replacement of the C1 atoms in PC1 and POCl by corresponding alcohols or thioalcohols; for example, by reacting a dichloride of the formula stepwise with a mercaptan of the formula R' SH and with a mercaptan of the formula R" SH preferably in the presence of a tertiary amine, in the process of which the reaction with the first mercaptan, in case R and R" are different, is carried out appropriately in the absence of a tertiary amine, or by reacting a mono-chloride of the formula (l-P: v11

with an alcohol or mercaptan of the formula R XH 17.7 Parts of methoxyethyldichlorophosphite are introduced into 100 parts by volume of benzene. Thereto is added dropwise at 20C under nitrogen a mixture of 18.2 parts of butylmercaptan and parts of tricthylamine in 50 parts by volume of benzene. The mixture is stirred for 2 hours at ambient temperature. For processing, the benzene solution is shaken repeatedly with water and the solvent thereafter evaporated in vacuo. 23.9 Parts of a colourless oil of the formula CH OC H OP(SC H n) n 1.5061 (Active substance No. 1)

are obtained as residue.

The following derivatives were manufactured analogously:

EXAMPLE 2 19.3 Parts of methoxyethyldichlorophosphite are introduced into parts by volume of benzene. Thereto is added dropwise at 10-20C a mixture of 18 parts of butylmercaptan and 20.5 parts of triethylamine in 50 parts by volume of benzene. The mixture is stirred overnight at ambient temperature. For processing, water is added, the benzene solution is shaken repeatedly with water and the solvent thereafter evapaorated in vacuo. 24.3 Parts of a yellowish oil of formula n 1.4980 (Active substance No. 12)

are obtained as residue.

The following phosphoric acid esters were manufactured analogously:

EXAMPLE 3 26 Parts of dibutyldithiochlorophosphate (b.p. 131C at 0.05 mm Hg) are introduced into 100 parts by volume of benzene. A mixture of 5.8 parts of allylalcohol and 10.5 parts of triethylamine in 20 parts of volume of benzene are added dropwise at 20-30C and the mixture stirred overnight at ambient temperature. For processing, the benzene solution is shaken repeatedly with water and the solvent thereafter evaporated in vacuo. 25.2 Parts of a light yellow oil of formula 1? (nC H S),P-OCH CH=CH 11,," 1.5304

(Active substance No. 20)

are obtained as residue.

The following esters can be manufactured in analogous manner:

foliation and 5 denotes total defoliation.

The resultsare listed in the following table:

Active Substance No. Dcfoliation DEF 4 Active Substance No. Formula 21 nc,11,,s ,P-oCH 11,? 1.5392

22 ("Cans )2PSCH2 11,, 1.5569

EXAMPLE 4 Dusting Agents Emulsion Concentrate Active substances that are readily soluble can also be formulated according to the following prescription:

20 parts of active substance 70 parts of xylene 10 parts of a mixture from a reaction product of an alkylphenol with ethylene oxide calcium dodecylbenzenesulphonate are mixed. On diluting with water to the desired concentration there results an emulsion that is capable of being sprayed.

EXAMPLE 5 Four months old cotton plants (with their capsules burst open) that have been raised in conditioning cabinets, were sprayed with concentrations of the various preparations containing 4 kg of active substance per hectare. Six days later, evaluation took place according to a grading system of l to 5, in which 1 denotes no de- EXAMPLE 6 Four months old cotton plants of the variety Delta Pine (approx. 1.20 m high) with -90% ripened, opened capsules, were treated in lots of 10.8 m in South Africa in April during hot, dry weather, with active substance concentrations of 2 kg a.s./ha and 4 kg a.s.lha. The amount of water used was 820 liters per hectare. Tri-(N-butyl)-trithiophosphate (=Folex) was used as comparative substance. Three parallel tests were carried out per active substance and concentration. The leaves of all test plants were counted before the treatment and 1 and 2 weeks after the treatment.

Results Comp.No. kg AS/ha Defoliation New Growth after after (No. of 1 week 2 weeks leaves per plant) 20 2 76.2 85.4 13.9 4 86.4 95.0 7.6 21 2 78.7 89.4 4.5 4 92.4 94.5 24.3 22 2 76.8 88.4 16.8 4 90.0 92.6 18.8 Folex 2 73.6 83.6 17.6

not tested Remarks:

The commercial preparation Folex (tri-(n-butyl)-trithiophosphite). even if applied at excess dosage, is not able to exceed a threshold value of approx. defoliation. In contrast thereto, preparations according to the invention clearly show, at both concentrations, a better and permanent defoliation.

We claim:

1. A compound of the formula 9 10 l in C H SC H OP-(SnC H R-OP(SnC4 )2 4. A compound according to claim 1 in which n is l.

5. The compound according to claim 4 which is 5 in which R is alkylthioalkylene wherein the alkylthio moiety has from i to 3 carbon atoms and the alkylene H moiety has from 2 to 4 carbon atoms, and n is the numfl ber 0 or 1.

2. A compound according to claim 1 in which n is O. 0 3. The compound according to claim 2 which is 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1 in which n is
 0. 3. The compound according to claim 2 which is C2H5-S-C2H4-O-P-(S-nC4H9)2
 4. A compound according to claim 1 in which n is
 1. 5. The compound according to claim 4 Which is 